The Old Alms House Cemetery sits within the Gettysburg National Military Park in Pennsylvania. The county Alms House complex, for sheltering the poor and mentally ill, stood in the vicinity at the time of the battle in 1863, and the cemetery remains on Barlow Knoll. (I haven’t been able to find a credible account of when the institution closed.) When we visited, there were markers with dates as recent as the previous year.
The grave markers are all rather simple – this is, after all, a cemetery for the poor. The monument for Asa Brown, “erected by friends,” is fancy in this context.
Most of the graves marked are for the very young or the very old.
It is also the resting place of those who could not be identified.
A Grave Concern 
I have visited the Almshouse Cemetery many, many times, and have always been saddened by the “Unknowns”. The idea that someone could live a life and then die without someone knowing who they were is pitiful. At least an effort was made to give them a marker to acknowledge that a human being now lies beneath the earth at that spot, unknown though they may be.